Ion implantation is a standard technique for introducing conductivity-altering impurities into a workpiece. A desired impurity material is ionized in an ion source, the ions are accelerated to form an ion beam of prescribed energy, and the ion beam is directed at the surface of the workpiece. The energetic ions in the beam penetrate into the bulk of the workpiece material and are embedded into the crystalline lattice of the workpiece material to form a region of desired conductivity.
In order for light-emitting diodes (LEDs) to gain more of the lighting market, improvements in efficiency and manufacturing cost may be required. LEDs, laser diodes, or other devices may be fabricated on compound semiconductors, such as GaN. One method of improving the efficiency of compound semiconductor devices is ELOG. ELOG uses a periodic mask structure to block the growth of GaN in some areas. Then some GaN will grow more laterally when it joins neighboring areas. This may result in a higher quality solid layer of GaN. Previous methods used a photoresist (PR) mask to block a portion of the implanted ions, but this adds cost and complexity. Accordingly, there is a need in the art for improved methods of ELOG.